Who was the Communist leader in Vietnam who wanted to unite both north and south under Communism?

Ho Chi Minh, a founding member of the French Communist Party after World War I, hoped to work from within to end France's dominion over Vietnam.  His father was a strong Vietnamese nationalist, and Ho Chi Minh followed the same political path.  During the 1920s and 1930s, Ho Chi traveled to China, where he familiarized himself with Mae Tse-sung's anticolonial revolutions; returning to Vietnam, he helped organize the IndoChina Communist Party in 1929.

In the South Ngo Dinh Diem defeated three separate groups to unite South Vietnam.  Knowing that the emperor, Bao Dai, was too weak, he assumed rule of the South. So, in 1954 Bao Dai gave Diem dictatorial powers in South Vietnam. In 1955 the Eisenhower administration helped create a new nation, the Government of the Republic of Viet Nam.  Diem was elected president in a dubious election the following year.  However, he was assasinated in 1963 by young military leaders who believed that he no longer possessed the confidence of the Vietnamese people.  By this time, the United States became involved supposedly in order to prevent a Communist takeover.  Beginning in 1959 troops were deployed; in 1960, because of the unpopularity of the Diem regime, Hanoi authorized the creation of the National Liberation Front as a common front controlled by the Communist Party. North Vietnam became infiltrated and troops and military supplies from the north came in by the infamous Ho Chi Minh Trail. Diem's paranoia, repression and incompetency eventually led to his defeat as a significant number of Vietnamese of the South began to support Communism and the Viet Minh.

In 1965 U.S. combat units began arriving.  Ten years later, the capture of Saigon by the North Vietnamese in April 1975 ended the Conflict that was never officially deemed a war.  58,000+ Americans died and thousands of others were wounded physically and mentally in this civil war of Vietnam.